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The dead of winter

Many new beekeepers are concerned about the dead bees that accumulate on or near the hive in winter. Every week I receive several questions about this, so I want to elaborate.

Even in the healthiest of colonies, bees die every single day. According to Bees of the World (O’toole and Raw) a normal-sized colony loses about a thousand bees per day in the summer. These losses are replaced by a busy queen that may lay upwards of a thousand eggs per day. Most of the summer losses are foragers that die on the job and we never even notice them. Since they are out of sight and out of mind, most beekeepers aren’t too concerned about these daily losses.

But bees continue to die every day even in winter. The losses are not as high because the bees are not foraging and because winter bees have special adaptations that allow them to live longer than summer bees. Still, many die every day, and they die at home where we can see them.

If you consider that your healthy colony may have 50,000 or maybe even 60,000 members going into the fall but may have only 20,000 come spring (WSU Extension) somewhere along the line you lost 30,000 to 40,000 bees. That’s a bunch.

For the sake of argument, I’ll take the smaller number of 30,000 and divide it by 182, which is the number of days in October, November, December, January, February, and March. That gives me 164 bee deaths per day. The larger number of 40,000 gives me 220 bee deaths per day.

Of course these numbers are approximations. But most people who write to me are concerned about “five or six dead bees” on the landing board or “two dozen dead bees on the snow.” As you can see, those numbers are just natural attrition and are nothing to worry about.

For years now my own hives have been within a short walk of my house. Nearly every day I walk up there (for my benefit more than theirs) and I flick the dead bees off the landing boards. What I’ve noticed is that a new pile of bees every day is a signal that all is well inside. Only a healthy colony has the manpower—er, beepower—to dispatch undertaker bees to clean up the bodies. On warmer days they fly them off and drop them on the ground, but on colder days they just shove them out the entrance. In either case, all is well.

Now I begin to get concerned when I see no bodies, because then I wonder if the colony is as strong as it should be. In fact, in several instances this was my first clue of a failing colony. It’s not a sure thing, but it is a piece of information you can use when making management decisions or when you are trying to decide if you should peek inside.

But don’t forget to look before you flick. A couple of years ago, I found the queen among the five or six dead bees at the entrance. I was able to combine that queenless hive with a nuc in the middle of winter, and I ended up with a vibrant, healthy hive by spring.

Rusty
HoneyBeeSuite

This bottom board came from a colony that overwintered successfully. Even though I removed a dozen or so bees every day, this thick mat of bees remained on the inside of the hive. The light-colored debris is from combs that were opened (bottom and right) and sugar cakes (top left).
This bottom board came from a colony that overwintered successfully. Even though I removed a dozen or so bodies every day, this thick mat of bees remained on the inside of the hive. The light-colored debris is from combs that were opened (bottom and right) and sugar cakes (top left).

Comments

Blake

Thank you! As a first year beek, I found this information to be very comforting. I just found your blog a few weeks ago and have really enjoyed catching up!

Ken

I worry about my bees because here in central Idaho the winter is cold. Lately, single digits and below and low teens in the day. (Hope it warms up). I even considered putting a reptile heater in to warm up the hive. (My wife talked me out of it. Said that God created bees and they have survived this long, so they probably will survive this winter [hope so]). When it was warmer I placed Reese patties in the hive and later candy boards. Well, I really look forward to spring. Your pictures give me hope. I don’t have that many dead bees. I would be interested on any comments about successful overwintering of bees in cold climates. I do know that bees are raised in these inhospitable conditions.
Willow Creek Honey

Rusty

Ken,

The problem with heating hives is that it can fool the bees into thinking it is warm outside. If they fly out of the hive in those temperatures they will be unable to return and they will die. Wives are always right.

Jacob N

It’s interesting how we see something we don’t understand and assume there is a problem. More often than not it is something normal or benign.

Rusty, Thank You, for another great post.

Nancy

Rusty,

You mentioned this briefly in an earlier post, and it’s a good thing. Yesterday one hive had several dozen dead at the entrance, and I surely would have panicked if I hadn’t read that.

But elsewhere you advise entrance reducers and mouse guards for winter. Should we remove those to brush the dead bees out? What about all the bodies on the screens? Leave them there till warmer weather?

Adding a note of my own advice: before setting up with bees, contact your county extension office, the best way to find a local bee club. Not only information but hands-on help may be available. I now have the luxury of a young couple, currently without bees of their own, to help pop lids off to replace sugar, pollen & grease patties. It makes a big difference to working quickly in marginal weather. If all goes well, I’ll “pay” them with some splits from mine in spring.

And a note to clubs: we’re considering a “Friends” level membership, to get some learners involved without having to commit to hives.

It’s all about community!

Nan

Rusty

Nan,

Once or twice during the winter, I take out the reducers and mouse guards and then reach in as far as possible with a stick or hive tool and sweep out as many dead as I can. In thirty seconds or so I can pull out a thick pile and then I put the hive back together. It is especially important that their path to the entrance is not blocked by dead bees. You want them to be able to take cleansing flights on warm days and you want them to have fresh air and good ventilation.

John Perdue

Rusty,

Very timely posting. Thanks a bunch.

I have a new hive (1st winter) and it has been so cold I can’t open the hive to gauge their health. I find several dead bees on the landing board each day when I look the hive over. They started the winter (southeast Texas) with one full mid-depth super full, but I would like to know how much has been consumed. I have installed an entrance reducer and have been feeding 1 cup water to 2 cups sugar which lasts about two weeks.

Jper….

Olof

Thank you for your post. I was starting to worry as a first year beekeeper in my backyard. I did feed them today and they finished 2 cups sugar to 1 cup water in less than a day. I thought that since they had 2 deeps full before winter that I wouldn’t need to feed, but man did that go fast. Should I keep feeding in the winter? I’m worried about it raising the moisture levels in the hive.

Rusty

Olof,

Well, if they need the feed then you have to feed them. Excess moisture is not good, but dry and dead is not good either. If you get a warmish day, you can open the hive and try to put the remaining frames of honey closer to the cluster. But if they are near the top of their hive and there is no honey nearby, you’ll have to feed them to save them.

James Lipscomb

I have one beehive. It had set in my yard several years empty. Then about four years ago a swarm took up residence in it. They thrived until last spring. Early in the spring they had been working merrily along until one day I saw many hundreds dead in front of the hive. It went downhill from then. Needless to say the wax worms and hive beetles finished them off.

I had intended to destroy the empty hive but before I did a new swarm went and cleaned it out. That was last spring. I had issues with robbers in the fall but the swarm defeated them and I feed them sugar syrup and the hive was very heavy. We have had a mild winter and the bees continued working until three days ago when the temperature dropped to 28. Yesterday I looked at them and there were hundreds dead on the ground. I swept them away and this morning more dead, maybe 100. I watched the hive a while in the dark and saw that the bees are walking out of the hive and jumping to the ground where they die in about a minute. They look healthy. There are a few drones but most are workers.

I am going to destroy the empty hive this time when bees are completely gone.

I would like to have some idea as to what is wrong. Working and flying one day and dead the next.

Rusty

James,

The first die-off you mention sounds a lot like a pesticide kill, but too late now to know for sure.

The most recent problem sounds different. It is impossible to tell from here, but bees that have been affected with a virus (such as those carried by Varroa) will sometimes fly out and die. It’s as if they know they are ill and so die away from the hive to keep the disease away from the hive. A bad infestation of mites can take down a large and healthy hive in a week. Having them come out at night, though, is weird. Where do you live?

Anna

Rusty, thank you once again for a great post! Now I’m not so worried about the quantity of dead that have accumulated this winter, I am still a little concerned with how many bees remain alive and whether they’ll make it through the winter dying off at the rate they are. The cluster seems to have moved up pretty quickly in the boxes – it almost seemed like the top of it ate through the newspaper I had resting on the top of the bars and is now eating the sugar/water/ProHealth mix I placed there a few days ago. That means they’re right up against the canvas of my quilt box (there were bees clinging to the underneath). I haven’t opened the boxes yet to see what is going on in the middle (I know the bottom box is empty). because I haven’t wanted to break their cluster. Any advice on how to assess their state? Or should I just keep putting sugar in that top rim box to keep them fed?

Rusty

Anna,

I’m always hesitant to open them up in the cold, but if they are eating the sugar, that is certainly a good sign.

Eddie

I live in San Francisco so winter is not as harsh as in other parts of the country and there is just about year round sources of pollen.

I started my hive last April and decided to go the 3 deep route and left the honey in the hive supers alone figuring it should give my bees a good store to get them through winter.

About 6 weeks ago we had temps at night hovering around the mid 30’s which is unusual for us (normally mid to high 40’s). I noticed a lot of bees on the screened bottom board and figured it was normal? Hive activity has slowed but they are still foraging. Looked today underneath and still saw a number of dead bees down there, but it doesn’t look like a massive number? I am wondering if the cadaver bees were able to clear out the batch from weeks earlier – the dead bees look like old bees mainly with some new dead.

Hard part being a first timer at all this is I have no previous experience to judge by. I am guessing/hoping all is working okay for the bees as long as I am seeing foraging and occasional orientation flights?

Do I need to scoop out the dead bees on the screened bottom or is it best to let the bees work on it?

Any encouragement or tips would be appreciated. The configuration of my hive is as follows: 3 deeps, 2 supers, screened bottom board sitting under a slatted rack and inner screened top cover. I’m not feeding syrup as they seem to be foraging just fine.

Rusty

Eddie,

There are always going to be dead bees because some will die everyday. The only time I clean the bottom board in the winter is if the entrance gets blocked. If so, I just pull out the entrance reducer and run a stick or hive tool in there and scrape out enough bodies that the lower entrance is no longer blocked.

Just because bees are foraging for food doesn’t mean they are finding anything. They may be finding it, especially in your area. But don’t assume they have enough food, check to be sure they do.

Eddie

Many thanks for the reply Rusty! 🙂 Supposedly (according to local SF beekeepers), there is a steady nectar flow from the Eucalyptus trees in our area that last from October to late May. There is a large Eucalyptus grove just a block and a half up from my house. Always there are flowers of some variety blooming.

The bees seem to be mostly coming back with their pollen baskets full – not sure how to tell whether they are carrying nectar too?

I checked a little after I saw your post and it looks like they have the three deeps utilized (with space for expansion on nearby frames). Sure wish I had more experience at this. I’m going to be adding a second hive in another part of my garden in late April – mainly so that I will have a ‘reference’ hive to compare to.

Justine

Hello!
Do you have a photo of what a winter cluster of bees looks like? I peeked into my hive today (Halloween– not winter, but very wet here) and I was alarmed at how small the cluster looks. It is very hard to gauge the population of a cluster, though… what I had thought was hundreds may have been thousands. It would be helpful to see what a winter cluster looks like from the inside!

Rusty

Justine,

No, I don’t have a photo. But imagine the cluster is shaped like a basketball. When you open the lid, you are just seeing the top of the curved outer shell. It is probably bigger than you imagine. Then too, the cluster expands or contracts with changes in temperature. It is bigger in warm weather and smaller in cold weather. This is one way the bees regulate the internal temperature.

MissMarianne

Rusty-

This morning I found a queen outside with a few other dead bees. As is normal, I find several everyday, but today I found the queen. Should I assume this hive is queenless or were there two queens? Or was this a late hatched queen who decided to take a mating flight? It’s cold and worst of all foggy here. Any suggestions? I have 3 other hives. One is an 8 frame and this one is a 10 frame. Of the other two, one is really mean!! but hardy.

All of my hives superseded this year and I have had lots of “queen events”! Suggestion? It’s November 29th!!!

Thank you!!

Rusty

Miss Marianne,

If it were me, I would assume the hive is queenless. I’ve only found a dead queen on the landing board in winter one time, and I immediately combined that hive with another using newspaper. The combined hive did well.

Sometimes a colony can have more than one queen, but the situation usually doesn’t last long. A queen “hatched” in the last month or two or three, depending on where you live, wouldn’t be able to mate in any case. Here, my drones were mostly gone by the end of August. I saw a few in September, but open mating late in the year is problematic.

If you get a warmish day, you can quickly check through the frames, but I doubt you will find another queen. And a virgin queen is useless. Whatever you do, don’t wait too long or you will begin to get laying workers.

MissMarianne

Rusty,

Thanks for your prompt reply to my “problem”! Since it’s cold and going through the hive sounds like a recipe for making things worse I have decided to combine. Now, I have a question about that!

I am planning on taking the queenless hive and moving it over to a QR hive. That means I need to take off the precious inner cover of my QR hive to put newspaper on and then the hive box from the now queenless colony?

So, I’m thinking to leave the queenless inner cover in place with its propolis seal and move it over. Depending on what I find… I’m sort of hoping they have all moved into the top box and I can remove the bottom box and clean it out, look for clues and store any drawn comb I find. But if they are in two boxes I will move both boxes on top of their new home. Does that sound like a plan to you? I’m just trying to figure out a way to leave the inner cover undisturbed. We are getting some dry weather the next couple of days. But the temp is low, 52 max for the day. Any suggestions or insights you have are appreciated!

Hopefully these bees will bolster my other hive and give them an even better chance at being robust in the spring. I guess I can make a split.

So, one more question. I have a very aggressive hive that was from a swarm I caught last March. They are hardy but small. If I combine with those bees I am thinking they might kill the new bees since they are really aggressive! I would like to re-queen that hive since they are so aggressive and thought that I would do that in the spring. However, being that they are a strong hive, would they benefit each other? more numbers? strong instincts? Thoughts? The last thing I want is more aggressive bees!!! But I am wanting these bees to go to a strong home. Just wondering if the temperament is different in the winter and they would more readily accept a colony? My other option is a hive that is not as strong but mellow.

Thanks Rusty!

Rusty

Miss Marianne,

Yes, you will have to remove the inner cover from the lower hive and replace it with newspaper. However, I don’t think of it as “precious.” If we become so averse to breaking the propolis seal that we fail to practice good beekeeping, then the inner cover hinders rather than enhances colony health. I never hesitate to break a propolis seal if I need to see or do something.

Furthermore, the weight of the hive boxes and the heat from inside the hive quickly reseals the hive. To me, it is a non-issue. And I consider 52 F degrees warm, nearly flying weather. Don’t worry about it.

Now your second question. I don’t think you can assume that a colony which is aggressive towards humans and/or pets is also aggressive toward other honey bees. Maybe it is, but I think you may be jumping to conclusions. At any rate, the reason for the newspaper is to allow the queen’s pheromones to slowly circulate through the two hives, so that all the bees “smell alike,” if you will. Once the pheromones are circulated throughout the two colonies, they will accept each other as nest mates. That’s the reason for doing it.

I think they will combine just fine. Then, come spring, you can replace the aggressive queen or split the hive as you mentioned and re-queen both halves. The more immediate problem is to get the queenless colony combined with another.

Bee Nice

Yesterday I also had a ‘queen event’ I am sad to say. I was treating my 7 hives with oxalic acid vapor and unfortunately when I pulled the spoon out I was presented with a half cremated queen. Fortunately I am aware of the loss and also fortuitously I came across your site today and I feel that I have some support in what direction to take to correct the loss. I will combine the hive with another using newspaper, the hives are all 2 deep – brood box with deep honey super on top – would you recommend adding both supers to make the hive 4 deep?

Rusty

Bee Nice,

That is really sad. You can do it either way, but just remember that twice the bees will eat almost twice the food. So if you decide to give just one super, monitor their food carefully in case they go through it faster than you expect.

MissMarianne

Rusty
Thanks for your great answers!! I’m on it. Just waiting for a break in the weather later today, and adding another sugar brick!
Happy Holidays!

MissMarianne

Hey Rusty!!

I did it! The queenless hive I moved was full of bees!! Two boxes! The top box was pretty heavy with honey stores and that is now on the very top.

I added it to the other hive with newspaper as you suggested. It is now 4 high….deep, shallow, deep shallow but I’m going to strap it down. This is now a BIG hive, which I am very happy about. We didn’t lose many bees in the process, I had my sister-in-law help me. It was 45 degrees. But not any forecast for much warmer so I went with it. I am really happy I did it! Thanks for the encouragement.